This application claims the benefit of Korean Application No. 97-57639, filed Nov. 3, 1997, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a speaker apparatus, and more particularly, to a speaker apparatus in which a sound wave is uniformly radiated to front and rear sides to thereby prevent distortion of sound due to one way vibration.
2. Description of the Related Art
Generally, a speaker radiates a sound wave through a free space after converting an electronic signal into a sound wave signal.
That is, when a strong magnetic field is generated by a magnet, an electric current flows at a voice coil disposed in the range of the magnetic field to generate a force so that a vibrating plate can vibrate by the force in order to radiate the sound wave.
In general, a conventional speaker as shown in FIG. 1 includes a vibrating plate 11, a bobbin 12 and a voice coil 13 disposed at an inner side of a frame 10, a damper 14 disposed at the frame 10 and a bobbin 12. An upper plate 15, a magnet 16, and a polepiece 17 are disposed at a lower side of the frame 10.
The voice coil 13 is wound at an outer side of the cylindrical-shaped bobbin 12 and moves integrally with the bobbin 12. The bobbin 12 has a front end connected to a lower side of the vibrating plate 11 and an outer side supported by the elastic damper 14. The polepiece 17 is disposed at a predetermined distance from an inner side of the bobbin 12, and the region between the polepiece 17 and the upper plate 15 serves to generate the magnetic field by the magnet 16.
The bobbin 12 vibrates axially according to Fleming""s left hand law when the electric current passes through the voice coil 13, and at the same time the vibrating plate 11 disposed at the front end of the bobbin 12 vibrates to radiate the sound.
However, the speaker apparatus as mentioned above involves many problems, such as the sound radiated from the front side of the speaker apparatus is distorted by one way vibration generated by a vibrating plate, the radiating distance of the sound decreases, and the quality of low frequency sound deteriorates. Also, there is a problem that the heat generated by the voice coil causes degradation of adhesives of the voice coil and breakage of the vibrating plate.
The present invention has been disclosed to solve the aforementioned problem and it is an object of the present invention to provide a speaker apparatus in which a sound wave is uniformly radiated from a vibrating plate to thereby prevent the distortion of sound and to thereby improve the quality of low frequency sound.
It is another object of the present invention to provide a speaker apparatus in which heat generated from the voice coil is effectively radiated to the outside.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
In order to achieve the above and other objects of the present invention, a speaker apparatus includes a bobbin to vibrate a vibrating plate according to a current applied to a voice coil, wherein a yoke is disposed at an inner side of the bobbin and spaced apart from the bobbin by a predetermined interval, and a sound wave guiding member is disposed at an inner side of the yoke so as to guide the sound wave to the front side and the rear side of the speaker apparatus.
As described above, according to the speaker apparatus of the present invention, the sound wave radiated from the speaker apparatus is guided by the sound wave guiding member to be radiated to the front and rear sides of the speaker apparatus so as to prevent one way vibration of the sound wave and to even more improve the quality of low frequency sound.
Further, the heat generated from the voice coil is radiated to the path for the sound wave formed in the yoke, to thereby prevent damage of adhesives of the voice coil by the heat or the failure of the vibrating plate in advance caused by the heat.
Further, a supporting member can be formed at the bottom side of the sound wave guiding member because the sound wave guiding member is formed at a bottom side thereof with a supporting portion.